The present invention relates generally to aerating and agitating pumps. Such pumps may, for example, comprise part of a waste treatment system for use in connection with an animal maintenance house of the type in which animal waste drops into a water filled ditch. A slurry of the water and waste is recirculated and aerated to encourage the growth of aerobic bacteria which reduces the waste to mainly carbon dioxide and water thereby minimizing the odor associated with the raising of animals such as swine.
Pumps such as for use in waste treatment systems should be capable of combining air with agitation so that slurry in a waste treatment system can be both aerated and agitated for recirculation within the system. Such pumps should desirably have a provision for adjusting the amount of air introduced under pressure to cause aeration and should be capable of pumping the slurry in a downward direction upon aeration and agitation. Such pumps should also employ an arrangement such as rotatable and stationary blades to provide agitation of the incoming slurry and mixture thereof with air.